@cyril
I did a clean 3.3.6 install with blog profile and installed Seblod 3.5.0.
Then I:
-created a test article
-changed Home link to Seblod->List&Search->Articles
-in Articles List&Search type, item tab I added custom classes to fields title and introtext.
When I now go to the homepage, my test article is listed and I have my custom classes for title and introtext.
Main template: protostar.
List template: seb_blog
List item template seb_one.
So
I cannot confirm the problem and I guess this is related to your
template somehow. Do you have this problem on an upgraded site or a new
install?